Attention Shoppers: Why Dynamic Range Matters

People sometimes ask me what kind of camera they should buy.  A short time later, they start asking for explanations of what all the “features” do and their relative importance when choosing a camera.

Ok, so here’s the thing:  there are many things to consider when purchasing a camera—resolution, FPS, flash sync speed, etc.  One thing I think novice camera buyers fail to fully appreciate is the dynamic range of whatever sensor is housed inside a camera body.  What is this dynamic range of which I speak?  Allow me to pontificate.

One definition of camera sensor dynamic range is provided on the DxOMark website.  They define it as: “the ratio between the highest and lowest gray luminance a sensor can capture. However, the lowest gray luminance makes sense only if it is not drowned by noise, thus this lower boundary is defined as the gray luminance for which the SNR is larger than 1. The dynamic range is a ratio of gray luminance; it has no defined unit per se, but it can be expressed in Ev, or f-stops.”

Right.  Got it.  

Actually, I think it’s a fine definitional statement.  For those of us with only a few functional neurons, however, I humbly offer a simplified alternate explanation.  I have little fear in doing this, as I know that readers of internet blogs have traditionally been among the most compassionate and friendly of audiences to ever participate in human interactions.  So here we go…

Imagine you’ve got thirteen cats in a line.  On the right is a pure black cat, and on the right is a pure white cat, and all the ones in the middle form a spectrum of gradually increasing or decreasing grayness.  The number 7 cat is a pure mid-tone grey—how convenient.  The dynamic range of your sensor dictates how many of these cats you can capture in a single exposure with reasonable detail. 

If, for example, your sensor has a very wide dynamic range, you may be able to capture detail in all of the cats including the fine silky hair of the black cat and the delicate patterns of the white lace on the white collar of the white cat—but you would need a very good sensor indeed for all of those hypothetical cats.  More realistically, the cameras I own and operate, for example, can capture most but not all of those cats. Let’s take a wild guess and say 8 or 9 of them with some reasonable amount of detail.  Which 8 or 9?  Well, the good news is that I get to have a little bit of input into that.  I can, for example, decide the black cat isn’t very important and abandon him to the shadows.  I can decide that the grey cat is most important and allow both the black and the white cat to get blown out.  Get it?

Some examples:

First, the same shot as my last post.  Now take a look and identify the darkest and the lightest spots in the photo.  Those are clues to the shot’s dynamic range.  While taking this shot, I was concerned mostly about how bright the moon was relative to the other important parts of the shot.  I wanted a nice shot that showed both the detail in the moon and some detail of the buildings and vegetation.  If the moon was too bright, I wouldn’t get it.  Turns out I was ok, because the moon had just risen and was still relatively close to the horizon.  It wasn’t at full brightness yet, probably due to atmospheric haze.  Looking at the histogram of the shot, I realized that I was capturing all of the shot’s dynamic range that I cared about.  Go me.

Full moon rising over Washington DC skyline; the Lincoln and Washington Monuments; and the U.S. Capitol Building, February 2013

Next, same shot, but a few minutes later after the moon had risen and had really brightened (remember, the moon is essentially reflecting full daylight).  This (unprocessed) shot is now pushing the dynamic range of my sensor and, therefore, forcing me to make some “artistic choices” about the shot.  Abandon the darker shadows and get a nice moon shot?  Let the moon get blown out and keep the detail in the bottom half of the frame?  Lose all self-respect, bracket it, and run it through HDR software (don’t think I won’t do it either).

So, here’s the moral of the story:  When considering the purchase of a new camera, check out the dynamic range and integrate that into your decision.  I recommend you check out the DxOMark website which gives their estimates of dynamic range for various sensors.  For example, they list 11.3 stops of dynamic range for landscape for a Nikon D3100, but they rate a Nikon D800 at 14.4.  Assuming these measurements are accurate, that’s almost three more stops of exposure for your shot. 

 

Yes, more DR will probably cost you more money.  No, you don’t need the most DR available to take good photos.  Yes, the Nikon D3100 is a great camera and you should be proud to own one.  This is just something to think about.  

Warning: Engage brain before pressing shutter button.

How to Be There

 ...By Red Badger Photography

So here's a shot of the moon...just as it's coming up over the horizon....when it's in the full phase....and happens to be in alignment with some of DC's landmarks....when seen from a place that has a clear line of sight.

Coincidence?  I think not.

So how to you get this shot--or one like it?  You have to plan it--that's how.

Ok, that's a lie.  The easy way is to troll some of your local photography blogs and meetup groups until someone else suggests that you show up at a certain time and place and start pressing the shutter release.  For example: check out Unexpected Treasures.

But, what if you actually wanted to do something other than follow directions like an obedient little lemming?  Then, my squeaky whiskered friend, you would need to do the planning thing.

So, while there are probably easier ways to do this, I'll give you a few humble tips on how to be in the right place at the right time.

1.  Scouting, scouting, and scouting.  Get out.  Get off the couch.  Get out of the car and walk away from the road.  Get those REI hiking shoes dirty.  Look around.  Find places that make you think, wow, this is a pretty cool scene -- and then ask yourself "What would make it even cooler?"  Bigfoot stepping out of the woods?  An airplane coming in for a landing?  Better lighting from the sun being at a different angle?  How about the tree foliage in a different season?  Maybe even an astronomical event like a moonrise. 

2.  If you do decide that the lighting (for the purposes of this post that's aka the sun or moon) needs to be better, then you've got a couple of options.  The hard way is to google yourself up some almanac data, and then use your trusty map and compass to plot it all out.  You do know how to use a map and compass right?  I mean, only an idiot would walk into the woods carrying more camera gear than food, water, and survival gear and NOT know basic land navigation right?  Good -- and since you're an expert I feel comfortable recommending to you a couple pieces of software that should make it easier.

• First, the Photographer's Ephemeris.
• Secondly, Stellarium.

Between the two of them, you should be able to figure out where and when things will rise and set, and from what angle the light will be falling.  No, I'm not going to tell you how to use them.  They come with help files.  (This goes back to that get off the couch thing we talked about.  You really need to work on that.)  So download them, use them.  Our world is a wonderful, awe-inspiring place and amazing things happen every day.  Go take a picture of them.

 Since I'm in a good mood though, if you really must take this photo, then here are some suggested times for you to be at N38.888212, W77.069310:

• October 16th, 2013: Waxing Gibbous Moon ~17:00 (just for practice)
• February 15th 2014: Waning Gibbous (98%) ~18:45
• September 9th 2014: Full ~19:40

 Have fun!


Equipment used for this photo:
Nikon D800, mirror lock up
Nikon 70-200 f/2.8G ED VRII
Manfrotto 055XPROB Tripod
Manfrotto 322RC2 Tripod Head
Cable Release

Oh...and one final hint...get there early, get set up well before hand.

Red Badger Photography

First Post and Flakes

This blog is to be about anything I like.  Following that logic, there will probably be a lot of pictures and food discussions.

The food will be good -- by my standards anyway.  But if you're the type to pay $42 dollars for some parsley and a dead snail--and then walk around telling people how you were tweeting that it was the most wonderful thing EVER--well, you may be disappointed.

More bad news folks, the pictures here will likely include some bad ones.  That's how I learn.  Perhaps, if anyone ever reads this, you can learn from my mistakes. 

Let's get started.  Here's a picture taken a few days ago during a recent snow-storm.  This storm was unusual enough to make me get my camera because the snow was coming down in actual snowflakes.  Snowflakes were the norm when I was a kid growing up out West, but I've gradually become accustomed to local snow, which is usually in the form of ugly little pellets or big shapeless wet blobs.  Not so the other night.  It was the real deal.

So, I grabbed the 'ol clicker and went out to my balcony to try my hand at snowflake photography.  I did this fully aware that I didn't have the right equipment, the right background, or the right lighting, but I thought I'd try anyway.  Here's the best of a bad lot:

Pretty crappy I know, especially when compared to the work of someone who has perfected the art of snowflake photography -- like this guy over at snowcrystals.com.  Then again, he's invented and spent the money for a pretty sweet snowflake photography rig.  Well played sir...well played.

What did we learn from this?  (This is the payoff if you've actually read this)

1.  Snowflake photography is macro photography, and requires all the special equipment and techniques thereunto pertaining
2.  My technique of spreading out a black cloth and hoping for the world's best snowflake to  fall on it right where my camera happened to be focused was pure foolishness.  Better to read the techniques described at the link I gave above.
3.  I was fairly pleased with my LED ring-light, which gave me the best illumination out of all of the options I had available.  Pretty cool.

4.  Most importantly, I think a bad night of standing outside in a calm and peaceful snow flurry, feeling the cool air, and enjoying the absolute unique and beautiful artwork created by our world one crystal at a time, is far better than a good night of sitting on the sofa watching N&tflix.  It was time well spent, even if I didn't get any good shots.

RBP Nature Photography